The mechanism and regulation of carbohydrate transport via the phosphotransferase system (PTS) in bacteria continue to be studied in our laboratory. Our ongoing research includes: 1) Physical and chemical characterization of homogeneous mannitol-specific Enzyme II from Escherichia coli and purification of the sorbitol-specific Enzyme II. 2) Kinetic analyses of the mechanism of these enzymes. 3) Reconstitution of transport of PTS sugars in synthetic membrane vesicles containing purified Enzyme II. 4) Continuing experiments on PTS-mediated regulation of lactose uptake and adenylate cyclase in osmotically shocked E. coli vesicles. 5) A study of the biosynthesis and structure of the mannitol Enzyme II using hybrid Co1E1 plasmids containing the gene coding for this protein.